Primary parenchymal squamous cell carcinoma of the kidney:A case report

BACKGROUND Primary squamous cell carcinoma(SCC)of the renal parenchyma is extremely rare,with only nine cases reported.CASE SUMMARY This study reports a 51-year-old man with primary SCC of the renal parenchyma.The patient was admitted with recurrent dull pain and discomfort in the right lumbar region,which had worsened over 2 weeks,accompanied by painful gross hematuria.SCC antigen(SCCA)levels were elevated,and imaging revealed a renal mass with associated calculi.The patient underwent laparoscopic unilateral nephrectomy and lymph node dissection.Postoperative pathology confirmed highly differentiated SCC with necrosis in the right renal parenchyma,with negative renal pelvis and ureter.The pathological stage was Pt3aN1M0.Four months after surgery,the tumor recurred with involvement of the liver,right psoas major muscle,and inferior vena cava.The patient refused chemotherapy and succumbed to the disease 6 months postoperatively due to disease progression.CONCLUSION We report a case of primary SCC of the renal parenchyma,a rare renal malignancy.The clinical symptoms,laboratory tests,and imaging findings are nonspecific,making accurate and timely diagnosis challenging.According to the literature,for patients with renal calculi accompanied by a renal mass,elevated serum SCCA levels,and magnetic resonance imaging showing cystic or cystic-solid masses within the kidney with pseudocapsules and heterogeneous mild enhancement,the possibility of this disease should be considered.

Ipsilateral retroperitoneal papillary renal cell carcinoma 27 years after simple nephrectomy for a renal abscess:A case report

BACKGROUND Cases of severe inflammatory renal disease and renal cell carcinoma(RCC)that occur simultaneously in the same kidney have been occasionally reported.However,extrarenal RCC that does not originate from the native kidney has rarely been reported.To our knowledge,this is the first reported case of RCC developing in the ipsilateral retroperitoneal space after a simple nephrectomy(SN)for inflammatory renal disease.CASE SUMMARY A 63-year-old woman was referred to our hospital following the incidental discovery of a left retroperitoneal mass without specific symptoms.Her medical history revealed a left SN 27 years ago due to a renal abscess.Magnetic resonance imaging of the abdomen revealed three oval masses in the left retroperitoneum.The masses were successfully excised,and subsequent pathology confirmed papillary RCC.After surgery,the patient remained disease-free for 11 years without adjuvant therapy.CONCLUSION Clinicians should be vigilant of RCC in patients with retroperitoneal masses,especially after SN for inflammatory renal disease.

Endobronchial metastasis secondary to renal clear cell carcinoma:A case report

BACKGROUND Endobronchial metastases(EBMs)are tumours that metastasise from a malignant tumour outside the lungs to the central and subsegmental bronchi,and are visible under a bronchofibrescope.Most EBMs are formed by direct invasion or metastasis of intrathoracic malignant tumours,such as lung cancer,oesophageal cancer or mediastinum tumours.Renal cell carcinoma(RCC),accounting for 2%to 3%of all tumours,is a common malignant tumour of the urinary system.Renal clear cell carcinoma(RCCC)constitutes the predominant pathological subtype of RCC,comprising approximately 70%to 80%of all RCC cases.RCCC can spread and metastasise through arterial,venous and lymphatic circulation to almost all organs of the body.Moreover,lung,bone,liver,brain and local recurrence are the most common metastatic neoplasms of RCCC.However,EBM from RCCC has a low complication rate and is often misdiagnosed as primary lung cancer.CASE SUMMARY A 71-year-old male patient who had undergone radical left nephrectomy 7 years prior due to RCCC was referred to our hospital due to a 1-mo history of productive cough.The results of an enhanced chest CT scan indicated the presence of a soft tissue nodule in the upper lobe of the left lung,and flexible bronchoscopy revealed a hypervascular lesion in the bronchus of the left lung's superior lobe.Therefore,the patient underwent thoracoscopic left superior lobe wedge resection,and pathology confirmed EBM from the RCCC.CONCLUSION EBM from RCCC has a low incidence and no characteristic clinical manifestations in the early stage.If a bronchial tumour is found in a patient with RCCC,the possibility of bronchial metastatic cancer should be considered.

Using MsfNet to Predict the ISUP Grade of Renal Clear Cell Carcinoma in Digital Pathology Images

Clear cell renal cell carcinoma(ccRCC)represents the most frequent form of renal cell carcinoma(RCC),and accurate International Society of Urological Pathology(ISUP)grading is crucial for prognosis and treatment selection.This study presents a new deep network called Multi-scale Fusion Network(MsfNet),which aims to enhance the automatic ISUP grade of ccRCC with digital histopathology pathology images.The MsfNet overcomes the limitations of traditional ResNet50 by multi-scale information fusion and dynamic allocation of channel quantity.The model was trained and tested using 90 Hematoxylin and Eosin(H&E)stained whole slide images(WSIs),which were all cropped into 320×320-pixel patches at 40×magnification.MsfNet achieved a micro-averaged area under the curve(AUC)of 0.9807,a macro-averaged AUC of 0.9778 on the test dataset.The Gradient-weighted Class Activation Mapping(Grad-CAM)visually demonstrated MsfNet’s ability to distinguish and highlight abnormal areas more effectively than ResNet50.The t-Distributed Stochastic Neighbor Embedding(t-SNE)plot indicates our model can efficiently extract critical features from images,reducing the impact of noise and redundant information.The results suggest that MsfNet offers an accurate ISUP grade of ccRCC in digital images,emphasizing the potential of AI-assisted histopathological systems in clinical practice.

Optimal sequential therapy using tyrosine kinase inhibitors as the first-line treatment in patients with metastatic renal cell carcinoma: A nationwide multicenter study

Objective:The purpose of the study was to identify the best sequence of therapy beginning with a tyrosine kinase inhibitor(TKI)as the first-line therapy for patients with metastatic renal cell carcinoma(mRCC)in terms of overall survival(OS),progression-free survival(PFS),and rates of discontinuation and adverse effects during the treatment period.Methods:This is a retrospective,nationwide multicenter study of patients with mRCC after diagnosis at 10 different tertiary medical centers in Korea from January 1992 to December 2017.We focused on patients at either“favorable”or“intermediate”risk according to the International mRCC Database Consortium criteria,and they were followed up(median 335 days).Finally,a total of 1409 patients were selected as the study population.We generated a Cox proportional hazard model adjusted for covariates,and the different therapy schemes were statistically tested in terms of OS as well as PFS.In addition,frequencies of discontinuation and adverse events were compared among the therapy schemes.Results:Of the primary patterns of treatment sequences(24 sequences),“sunitinib epazopanib”and“sunitinibeeverolimuseimmunotherapy”showed the most beneficial results in both OS and PFS with significantly lower hazards than“sunitinib”,which is the most commonly treated agent in Korea.Considering that the“TKIeTKI”structure showed relatively higher discontinuation rates with higher adverse effects,the overall beneficial sequence would be“sunitinibeeverolimuseimmunotherapy”.Conclusion:Among several sequential therapy starting with TKIs,“sunitinibeeverolimuse immunotherapy”was found to be the best scheme for mRCC patients with“favorable”or“intermediate”risks.

Incidental renal cell carcinoma post bilateral nephrectomy in autosomal dominant polycystic kidney disease

BACKGROUND Renal cell carcinoma(RCC)is more common in patients with autosomal dominant polycystic kidney disease(ADPKD)than in the general population.Diagnosing RCC in ADPKD is challenging due to the presence of multiple renal cysts,often leading to delays and difficulties in distinguishing RCC from cyst infection or hemorrhage.A total of 38 kidneys were excised from 19 patients,with a mean age of 56.8 years and an average hemodialysis duration of 84.2 months.Eight patients underwent open nephrectomies,and 11 underwent hand-assisted laparoscopic nephrec-tomies.RCC was detected in 15.8%of kidneys,affecting 21.1%of patients.Two patients had multifocal RCC in both kidneys.All RCC cases were pT1 stage,with the largest lesion averaging 16.5 mm in diameter.The average operative duration was 120 minutes,with intraoperative blood loss averaging 184.2 mL.Five patients required blood transfusions.Postoperative complications occurred in five patients,with a mean hospital stay of 17.1 days.The mean follow-up period was 28.1 months.CONCLUSION The prevalence of RCC is higher in patients with ADPKD with ESRD than in those with ESRD alone.Thus,clinicians should be cautious and implement surveillance programs to monitor the development of RCC in patients with ADPKD,particularly those on dialysis.

Toripalimab in combination with chemotherapy effectively suppresses local recurrence and metastatic sarcomatoid renal cell carcinoma:A case report

BACKGROUND Sarcomatoid renal cell carcinoma(SRCC)is a rare variant of renal cell carcinoma associated with an unfavorable prognosis.The efficacy of conventional chemo-therapy and targeted therapies are limited,whereas the emergence of immune checkpoint inhibitor has introduced new avenues for managing advanced SRCC.CASE SUMMARY A 77-year-old female patient was referred to our hospital following the incidental detection of a right kidney tumor without specific symptoms.The tumor was successfully resected,and subsequent pathological examination confirmed SRCC.She experienced both local recurrence and distant metastasis eight months after the initial laparoscopic resection.Following six cycles of toripalimab combined with pirarubicin chemotherapy,the patient achieved a partial response.Subse-quently,the patient attained an almost-complete continuous response to toripa-limab monotherapy maintenance for an additional six cycles.She has not experienced disease progression for 15 months,and her overall survival has reached 24 months thus far.CONCLUSION Combination therapy with programmed death 1 antibodies and cytotoxic agents may be a recommended first-line treatment approach for SRCC.

Low expression of fatty acid oxidation related gene ACADM indicates poor prognosis of renal clear cell carcinoma and is related to tumor immune infltration

This research aims to identify the key fatty acid beta-oxidation(FAO)genes that are altered in kidney renal clear cell carcinoma(KIRC)and to analyze the role of these genes in KIRC The Gene Expression Omnibus(GEO)and FAO datasets were used to identify these key genes.Wilcoxon rank sum test was used to assess the levels of acyl-CoA dehydrogenase medium chain(ACADM)between KIRC and non cancer samples.The logistic regression and Wilcoxon rank sum test were used to explore the association between ACADM and clinical features.The diagnostic performance of ACADM for KIRC was asessed using a diagnostic receiver operating ch aracteristic(ROC)curve.The co-expressed genes of ACADM were identifed in LinkedOmics database,and their function and pathway enrichment were analyzed.The correlation between ACADM expression level and immune infitration was analyzed by Gene Set Variation Analysis(GSVA)method Additionally,the proliferation,migration,and invasion abilities of KIRC cells were assessed after overexpressing ACADM.Following differential analysis and intersection,we identifed six hub genes,induding ACADM.We found that the expression level of ACADM was decreased in KIRC tissues and had a better diagnostic efect(AUC=0.916).Survival analysis suggested that patients with decreased ACADM expression had a worse prognosis.According to correlation analysis,a variety of dinical features were associated with the expression level of ACADML By analyzing the infiltration level of immune cells,we found that ACADM may be related to the enrichment of immune cells.Finally,ACADM overexpression inhibited proliferation,migration,and invasion of KIRC cells.In conclusion,our findings suggest that reduced ACADM expression in KIRC patients is indicative of poor prognosis.These results imply that ACADM may be a diagnostic and prognostic marker for individuals with KIRC,offering a reference for dinicians in diagnosis and treatment.

Comprehensive assessment of the association between tumorinfiltrating immune cells and the prognosis of renal cell carcinoma

BACKGROUND According to current statistics,renal cancer accounts for 3%of all cancers world-wide.Renal cell carcinoma(RCC)is the most common solid lesion in the kidney and accounts for approximately 90%of all renal malignancies.Increasing evi-dence has shown an association between immune infiltration in RCC and clinical outcomes.To discover possible targets for the immune system,we investigated the link between tumor-infiltrating immune cells(TIICs)and the prognosis of RCC.AIM To investigate the effects of 22 TIICs on the prognosis of RCC patients and iden-tify potential therapeutic targets for RCC immunotherapy.METHODS The CIBERSORT algorithm partitioned the 22 TIICs from the Cancer Genome Atlas cohort into proportions.Cox regression analysis was employed to evaluate the impact of 22 TIICs on the probability of developing RCC.A predictive model for immunological risk was developed by analyzing the statistical relationship between the subpopulations of TIICs and survival outcomes.Furthermore,multi-variate Cox regression analysis was used to investigate independent factors for the prognostic prediction of RCC.A value of P<0.05 was regarded as statistically significant.RESULTS Compared to normal tissues,RCC tissues exhibited a distinct infiltration of im-mune cells.An immune risk score model was established and univariate Cox regression analysis revealed a significant association between four immune cell types and the survival risk connected to RCC.High-risk individuals were correlated to poorer outcomes according to the Kaplan-Meier survival curve(P=1E-05).The immunological risk score model was demonstrated to be a dependable predictor of survival risk(area under the curve=0.747)via the receiver operating characteristic curve.According to multivariate Cox regression analysis,the immune risk score model independently predicted RCC patients'prognosis(hazard ratio=1.550,95%CI:1.342–1.791;P<0.001).Finally,we established a nomogram that accurately and comprehensively forecast the survival of patients with RCC.CONCLUSION TIICs play various roles in RCC prognosis.The immunological risk score is an independent predictor of poor survival in kidney cancer cases.

Eosinophilic solid and cystic renal cell carcinoma with aggressive behavior:Two case reports

BACKGROUND Eosinophilic solid and cystic(ESC)renal cell carcinoma(RCC),a unique and emerging subtype of RCC,has an indolent nature;in some rare instances,it may exhibit metastatic potential.Current cases are inadequate to precisely predict the clinical outcome of ESC RCC and determine treatment choices.CASE SUMMARY Herein,we report two patients with ESC RCC.Patient 1 was a young woman with classical pathological characteristics.Patient 2 was a 52-year-old man with multifocal metastases,involving the pulmonary hilar and mediastinal lymph nodes,liver,brain,mesosternum,vertebra,rib,femur,and symphysis pubis.Awareness of ESC RCC,along with its characteristic architecture and immunophenotype,would contribute to making a definitive diagnosis,even on core biopsy samples.CONCLUSION The discovery of ESC RCC molecular signatures may provide new therapeutic strategies in the future.

Advances in treatment strategies for non–clear cell renal cell carcinoma

Renal cell carcinoma is the sixth most commonly diagnosed cancer in men and the tenth in women,with clear cell renal cell carcinoma accounting for nearly 75%of cases.The remaining 25%consists of non–clear cell renal cell carcinoma,a diverse and less prevalent group.Although current treatments for clear cell types are well-defined,progress in treating non–clear cell renal cell carcinoma has been limited owing to its heterogeneity and rarity,relying primarily on findings from small-scale phase Ⅱ clinical trials.This review examined recent advancements in the treatment of non–clear cell renal cell carcinoma,particularly in the areas of immunotherapy and targeted therapy.

Network pharmacology and molecular docking analysis reveal insights into the molecular mechanism of Gualou Qumai Wan in clear cell renal cell carcinoma

Background:To initially clarify the potential therapeutic targets and pharmacological mechanism regarding Gualou Qumai Wan(GQW),a kind of traditional Chinese medicine(TCM),in clear cell renal cell carcinoma(ccRCC)by virtue of the network pharmacology analysis and molecular docking analysis.Methods:The screening of bioactive components and targets of GQW was based on the Traditional Chinese Medicine System Pharmacology(TCMSP)and the UniProt platform served for standardizing their targets.Online Mendelian Inheritance in Man(OMIM),PharmGkb,TTD,DrugBank and GeneCards databases were searched to collect the disease targets of ccRCC.Cytoscape assisted in constructing herb-compound-target(H-C-T)networks.The STRING database was searched for constructing the target protein-protein interaction(PPI)networks,while the R programming language served for analyzing GO functional terms and the KEGG pathways related to potential targets.Analyses of core genes related to survival and tumor microenvironment(TME)were conducted respectively based on the GEPIA2 database and TIMER 2.0 database.Human Protein Atlas(HPA)and The Cancer Genome Atlas(TCGA)helped to obtain core genes’protein expression as well as transcriptome expression level.Autodock Vina software validated the molecular docking regarding GQW components and pivotal targets.Results:The constructed H-C-T networks mainly had 33 compounds and 65 targets.A topological analysis of the PPI network identified that ESR1,AKT1,HIF1A,PTGS2,TP53 and VEGFA serve as core targets in the way GQW affects ccRCC.According to the GO and KEGG pathway enrichment analyses,the effects of GQW are mediated by genes related to hypoxia and oxidative stress as well as the Chemical carcinogenesis-receptor activation and PI3K-Akt signaling pathways.AKT1 shows a close relation to the recruitment of various immune cells and can remarkably affect disease prognosis according to reports.Molecular docking and molecular dynamics simulations showed that diosgenin has higher affinity with core targets.Conclusion:The study makes a comprehensive explanation of the biological activity,potential targets,as well as molecular mechanism regarding GQW against ccRCC,which promisingly assists in revealing the action mechanism of TCM formulae in disease treatment and the respective and scientific basis.

Sustained long-term clinical and radiological response with sunitinib for metastatic renal-cell carcinoma (RCC)

The authors herein report the case of a 67-year-old woman with metastatic renal-cell carcinoma (RCC), who has had a sustained clinical and stable radiological response to long-term therapy with an oral multi-targeted tyrosine kinase inhibitor (TKI), sunitinib with minimal lasting toxicity.

MiR-144 Inhibits Cell Proliferation of Renal Cell Carcinoma by Targeting MTOR

Micro RNAs（mi RNAs） modulate the expression of tumorigenesis-related genes and play important roles in the development of various types of cancers. It has been reported that mi R-144 is dysregulated and involved in multiple malignant tumors, but its role in renal cell carcinoma（RCC） remains elusive. In this study, we demonstrated mi R-144 was significantly downregulated in human RCC. The decreased mi R-144 correlated with tumor size and TNM stage. Moreover, overexpression of mi R-144 in vitro suppressed RCC cell proliferation and G2 transition, which were reversed by inhibition of mi R-144. Bioinformatic analysis predicted that m TOR was a potential target of mi R-144, which was further confirmed by dual luciferase reporter assay. Additionally, the examination of clinical RCC specimens revealed that mi R-144 was inversely related to m TOR. Furthermore, knocking down m TOR with si RNA had the same biological effects as those of mi R-144 overexpression in RCC cells, including cell proliferation inhibition and S/G2 cell cycle arrest. In conclusion, our results indicate that mi R-144 affects RCC progression by inhibiting m TOR expression, and targeting mi R-144 may act as a novel strategy for RCC treatment.

Orthotopical transplantation of human renal carcinoma tissue into nude mice and the establishment of a high metastatic cell line MRCC

Objective To establish a SOI model of human renal carcinoma and a high metastatic cell subline. Methods A human renal cell line RCC-9863 has been established by inoculating a human renal tumor tissue into nude mice s. c.. When RCC-9863 passaged for 20 times, the tissue from the same xemotransplant tumor were used to construct SOI model. Cultured the metastatic tissue in vitro, the tumor cell suspension was then injected orthotopically, The metastatic tissue obtained underwent the same procedure again. At last, the metastatic tumor was cultured in vitro and cloned. Results 15 days later, a tumor mass sized 1. 7 cm × 0. 6 cm in the nude mouse’s renal parenchyma was grown which lobulated, rude, and with multiply blood vessels and 55 days later later the mouse became moribund and metastases in the lungs were formed. The transplanted renal tumor in the SOI model grew fast and invasively and metastasized to lungs, lymphatic node and liver. A subline, MRCC, with metastatic ability to the lung was selected.

Pathological clavicular fracture as first presentation of renal cell carcinoma: a case report and literature review

Renal cell carcinoma(RCC) accounts for approximately 3% of all cancer cases. RCCs usually metastasize to the lungs, bones, liver, or brain. Only <1% of patients with bone metastases manifested clavicular RCC metastases. Thus, clavicular metastasis as the initial presentation of RCC is extremely rare. We report a patient with RCC metastasis to the left clavicle, which was first presented with pain caused by a pathological fracture. Magnetic resonance image revealed a renal tumor, and technetium-99m–methylene diphosphonate bone scintigraphy showed multiple osseous metastases. The patient eventually underwent surgery to remove the lateral end of the left clavicle and right kidney. Histopathology revealed renal tumor and clear cell carcinoma in the clavicle. Finally, we review 17 cases of clavicular metastases originating from different malignancies.

Molecular genetics and immunohistochemistry characterization of uncommon and recently described renal cell carcinomas

Renal cell carcinoma （RCC） compromises multiple types and has been emerging dramatically over the recent several decades. Advances and consensus have been achieved targeting common RCCs, such as clear cell carcinoma, papillary RCC and chromophobe RCC. Nevertheless, little is known on the characteristics of several newly-identified RCCs, including clear cell （tubulo） papillary RCC, Xpl 1 translocation RCC, t（6;11） RCC, succinate dehydrogenase （SDH）-deficient RCC, acquired cystic disease- associated RCC, hereditary leiomyomatosis RCC syndrome-associated RCC, ALK translocation RCC, thyroid-like follicular RCC, tubulocystic RCC and hybrid oncocytic/chromophobe tumors （HOCT）. In current review, we will collect available literature of these newly-described RCCs, analyze their clinical pathologic characteristics, discuss their morphologic and immunohistologic features, and finally summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of RCCs, and eventually promote clinical management strategies.

Review of renal cell carcinoma and its common subtypes in radiology

Representing 2%-3% of adult cancers, renal cell carcinoma(RCC) accounts for 90% of renal malignancies and is the most lethal neoplasm of the urologic system. Over the last 65 years, the incidence of RCC has increased at a rate of 2% per year. The increased incidence is at least partly due to improved tumor detection secondary to greater availability of high-resolution cross-sectional imaging modalities over the last few decades. Most RCCs are asymptomatic at discovery and are detected as unexpected findings on imaging performed for unrelated clinical indications. The 2004 World Health Organization Classification of adult renal tumors stratifies RCC into several distinct histologic subtypes of which clear cell, papillary and chromophobe tumors account for 70%, 10%-15%, and 5%, respectively. Knowledge of the RCC subtype is important because the various subtypes are associated with different biologic behavior, prognosis and treatment options. Furthermore, the common RCC subtypes can often be discriminated non-invasively based on gross morphologic imaging appearances, signal intensity on T2-weighted magnetic resonance images, and the degree of tumor enhancement on dynamic contrast-enhanced computed tomography or magnetic resonance imaging examinations. In this article, we review the incidence and survival data, risk factors, clinical and biochemical findings, imaging findings, staging, differential diagnosis, management options and posttreatment follow-up of RCC, with attention focused on the common subtypes.

Advances of multidetector computed tomography in the characterization and staging of renal cell carcinoma

Renal cell carcinoma(RCC) accounts for approximately 90%-95% of kidney tumors. With the widespread use of cross-sectional imaging modalities, more than half of RCCs are detected incidentally, often diagnosed at an early stage. This may allow the planning of more conservative treatment strategies. Computed tomography(CT) is considered the examination of choice for thedetection and staging of RCC. Multidetector CT(MDCT) with the improvement of spatial resolution and the ability to obtain multiphase imaging, multiplanar and threedimensional reconstructions in any desired plane brought about further improvement in the evaluation of RCC. Differentiation of RCC from benign renal tumors based on MDCT features is improved. Tumor enhancement characteristics on MDCT have been found closely to correlate with the histologic subtype of RCC, the nuclear grade and the cytogenetic characteristics of clear cell RCC. Important information, including tumor size, localization, and organ involvement, presence and extent of venous thrombus, possible invasion of adjacent organs or lymph nodes, and presence of distant metastases are provided by MDCT examination. The preoperative evaluation of patients with RCC was improved by depicting the presence or absence of renal pseudocapsule and by assessing the possible neoplastic infiltration of the perirenal fat tissue and/or renal sinus fat compartment.

Long Non-coding RNA MEG3 Induces Renal Cell Carcinoma Cells Apoptosis by Activating the Mitochondrial Pathway

Summary： This study aimed to examine the effect of long non-coding RNA （LncRNA） MEG3 on the biological behaviors of renal cell carcinoma （RCC） cells 786-0 and the possible mechanism. MEG3 expression levels were detected by RT-qPCR in Rmaor tissues and adjacent non-tumor tissues from 29 RCC patients and in RCC lines 786-0 and SN12 and human embryonic kidney cell line 293T. Plasmids GV144-MEG3 （MEG3 overexpression plasmid） and GV144 （control plasmid） were stably transfected into 786-0 cells by using lipofectamine 2000. Cell viabilities were determined by MTT, cell apoptosis rates by flow cytometry following PE Annexin V and 7AAD staining, apoptosis-related protein expressions by Western blotting, and Bcl-2 mRNA by RT-qPCR in the transfected cells. The results showed that MEG3 was evidently downregulated in RCC tissues （P〈0.05） and RCC cell lines （P〈0.05）. The viabilities of 786-0 cells were decreased significantly after transfection with GV144-MEG3 for over 24 h （P〈0.05）. Consistently, the apoptosis rate was significantly increased in 786-0 cells transfected with GV144-MEG3 for 48 h （P〈0.05）. Furthermore, overexpression of MEG3 could reduce the expression of Bcl-2 and procaspase-9 proteins, enhance the expression of cleaved caspase-9 protein, and promote the release of cytochrome c protein to cytoplasm （P〈0.05）. Additionally, Bcl-2 mRNA level was declined by MEG3 overexpression （P〈0.05）. It was concluded that MEG3 induces the apoptosis of RCC cells possibly by activating the mitochondrial pathway.